Conventionally, a rotating electrical machine includes a motor housing that opens in one end in an axis of rotation direction. A stator is fixed to an inner circumferential surface of the motor housing. A rotor is rotatably mounted in the motor case so as to face the stator in a radial direction. See, for example, JP 2013-207968. In such a conventional rotating electrical machine, a heat sink is disposed at an opening of the motor housing. A control substrate that controls a rotation of a rotor is mounted to the heat sink. Heat generated by circuit elements of the control substrate are dissipated through the heat sink.